LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY com IS
PORT(
  a,b:IN STD_LOGIC_VECTOR(3 DOWNTO 0);
  q:OUT STD_LOGIC_VECTOR(1 DOWNTO 0));
END com;
ARCHITECTURE com_4p OF com IS
BEGIN
  PROCESS(a,b)
    BEGIN
      IF (a<b) THEN
        q<="00";
      ELSIF (a>b) THEN
        q<="01";
      ELSE
        q<="10";
      END IF;
  END PROCESS;
END com_4p;    
